No bonding required for pavers over deep sand with no concrete?

[nuttyp]

As I looked at the pictures in this post Ladder anchors don't have drainage I was reminded that my entire lanai is pavers over deep sand with no concrete under the pavers. Does anyone know why pavers don't need to be bonded in such a case? I don't get shocks and I have not (yet) tested for stray voltages from other items (water, rails, etc) to the pavers, just wondering if/how the pavers over sand are an exception to the bonding grid rules. My build was by the former owner.

 

[PoolGate]

Bonding is still required for pavers.

 

[JamesW]

A pool bonding grid is used to create a safe zone around a pool by connecting the pool's structural steel to the perimeter surface.

A single wire can also be used to bond a pool's perimeter, but it doesn't create the same level of safety as a grid.

Here are some things to consider when using a pool bonding grid or single wire:

Grid structure

The grid should cover the pool's contour and extend 3 feet beyond the inside walls.

It should be secured within or under the pool, 4–6 inches below grade level.

The grid should be made of a 12-inch by 12-inch network of conductors in a perpendicular grid pattern.
Single wire

The single wire should be an 8-gauge or larger bare solid conductor that follows the pool's contour.

It should be secured within or under the perimeter surface, 4–6 inches below grade level.

Bonding points

The grid or single wire should be connected to the pool at a minimum of four points that are evenly spaced around the pool.

Nonconductive pool shells

For nonconductive pool shells, bonding at four points is not required.

Perimeter surface

The perimeter surface includes unpaved surfaces, concrete, and other types of paving.

 

[JamesW]

2020 Code Language:

680.26(B)(2) Perimeter Surfaces. The perimeter surface to be bonded shall be considered to extend for 1 m (3 ft) horizontally beyond the inside walls of the pool and shall include unpaved surfaces and other types of paving. Perimeter surfaces separated from the pool by a permanent wall or building 1.5 m (5 ft) in height or more shall require equipotential bonding only on the pool side of the permanent wall or building. Bonding to perimeter surfaces shall be provided as specified in 680.26(B)(2)(a), (B)(2)(b), or (B)(2)(c) and shall be attached to the pool reinforcing steel or copper conductor grid at a minimum of four points uniformly spaced around the perimeter of the pool. For nonconductive pool shells, bonding at four points shall not be required.

(a) Structural Reinforcing Steel. Structural reinforcing steel shall be bonded in accordance with 680.26(B)(1)(a).

(b) Copper Ring. Where structural reinforcing steel is not available or is encapsulated in a nonconductive compound, a copper conductor(s) shall be utilized where the following requirements are met:

(1) At least one minimum 8 AWG bare solid copper conductor shall be provided.

(2) The conductors shall follow the contour of the perimeter surface.

(3) Only listed splicing devices or exothermic welding shall be permitted.

(4) The required conductor shall be 450 mm to 600 mm (18 in. to 24 in.) from the inside walls of the pool.

(5) The required conductor shall be secured within or under the perimeter surface 100 mm to 150 mm (4 in. to 6 in.) below the subgrade.

(c) Copper Grid. Where structural reinforcing steel is not available or is encapsulated in a nonconductive compound, copper grid shall be utilized where the following requirements are met:

(1) The copper grid shall be constructed of 8 AWG solid bare copper and be arranged in accordance with 680.26(B)⁠(1)⁠(b)⁠(3).

(2) The copper grid shall follow the contour of the perimeter surface extending 1 m (3 ft) horizontally beyond the inside walls of the pool.

(3) Only listed splicing devices or exothermic welding shall be permitted.

(4) The copper grid shall be secured within or under the deck or unpaved surfaces between 100 mm to 150 mm (4 in. to 6 in.) below the subgrade.

2017 Code Language:

680.26(B)(2) Perimeter Surfaces. The perimeter surface to be bonded shall be considered to extend for 1 m (3 ft) horizontally beyond the inside walls of the pool and shall include unpaved surfaces and other types of paving. Perimeter surfaces separated from the pool by a permanent wall or building 1.5 m (5 ft) in height or more shall require equipotential bonding only on the pool side of the permanent wall or building. Bonding to perimeter surfaces shall be provided as specified in 680.26(B)(2)(a) or (2)(b) and shall be attached to the pool reinforcing steel or copper conductor grid at a minimum of four (4) points uniformly spaced around the perimeter of the pool. For nonconductive pool shells, bonding at four points shall not be required.

(a) Structural Reinforcing Steel. Structural reinforcing steel shall be bonded in accordance with 680.26(B)(1)(a).

(b) Alternate Means. Where structural reinforcing steel is not available or is encapsulated in a nonconductive compound, a copper conductor(s) shall be utilized where the following requirements are met:

(1) At least one minimum 8 AWG bare solid copper conductor shall be provided.

(2) The conductors shall follow the contour of the perimeter surface.

(3) Only listed splices shall be permitted.

(4) The required conductor shall be 450 mm to 600 mm (18 in. to 24 in.) from the inside walls of the pool.

(5) The required conductor shall be secured within or under the perimeter surface 100 mm to 150 mm (4 in. to 6 in.) below the subgrade.

 

[JamesW]

680.26(B)(2) Perimeter Surfaces.
Revised code language now allows a copper grid for equipotential bonding of perimeter surfaces adjacent to a pool.

Revised code language now allows a copper grid for equipotential bonding of perimeter surfaces adjacent to a pool.

Code Change Summary: Revised code language now allows a copper grid for equipotential bonding of perimeter surfaces adjacent to a pool.

During the first draft stage of the 2020 NEC® code development process, a public input was rejected to delete the existing allowance of a #8 AWG bare solid copper conductor as an equipotential bonding means for the perimeter deck around a pool and replace it with a copper bonding grid.

The substantiation was that a single bare solid copper conductor performed insufficiently for its intended purpose according to tests conducted by National Electric Energy Testing Research and Applications Center (NEETRAC), Electric Power Research Institute (EPRI), and ENEREX.

Public comments received during the second draft stage of the 2020 NEC® development process resulted in the code making panel allowing the previous #8 AWG solid bare copper conductor to remain and a new allowance to use a copper bonding grid for equipotential bonding of the perimeter surfaces.

One requirement is that the copper grid must comply with 680.26(B)(1)(b)(3) and be arranged in a 12 inch by 12 inch network of conductors in a uniformly spaced perpendicular grid pattern with a tolerance of 4 inches.

Overall Change.

Voltage levels are changing in many areas of the NEC. Question: Would the fuse on the left be suitable in a PV source circuit where 15 PV modules were wired in series, if each module had an open circuit voltage of 42 volts?

www.electricallicenserenewal.com

 

[JamesW]

Does anyone know why pavers don't need to be bonded in such a case?

How do you know that there is no bonding?

At a minimum, there should be a bare, solid, copper #8 AWG wire around the perimeter of the pool.

In my opinion, there should always be a metal grid used on all pools for the perimeter surfaces regardless of the type of decking.

The grid can be copper, steel wire mesh, rebar (not epoxy coated) or other appropriate metal gridwork.

 

[PoolGate]

How do you know that there is no bonding?

At a minimum, there should be a bare, solid, copper #8 AWG wire around the perimeter of the pool.

In my opinion, there should always be a metal grid used on all pools for the perimeter surfaces regardless of the type of decking.

The grid can be copper, steel wire mesh, rebar (not epoxy coated) or other appropriate metal gridwork.

Are the pavers more than 3 feet from the pool? The bonding wire is required to be 2 feet from the pool. If the pavers are further away, I assume they are part of the pool bonding grid even though you might dig and not find any bonding wire (or grid).

 

[JamesW]

The bonding wire is required to be 2 feet from the pool.

Where does the code say 2 feet?

Edit.

2. Copper Ring. Where structural reinforcing steel is not available or is encapsulated in a nonconductive compound, a copper
conductor(s) shall be utilized where the following requirements are met:
1. At least one minimum 8 AWG bare solid copper conductor shall be provided.
2. The conductors shall follow the contour of the perimeter surface.
3. Only listed splicing devices or exothermic welding shall be permitted.
4. The required conductor shall be 18 in. to 24 in. from the inside walls of the pool.
5. The required conductor shall be secured within or under the perimeter surface to 4 in. to 6 in below the subgrade

 

[JamesW]

The bonding wire for a swimming pool should be located within 5 feet horizontally from the inside wall of the pool; meaning it should be attached to all metal parts within that 5-foot radius around the pool perimeter.

 

[JamesW]

The requirement for bonding perimeter surfaces applies to paved and unpaved surfaces, such as a lawn surrounding a permanently installed aboveground swimming pool.

Where the paved portion of the perimeter surface extends less than 3 feet horizontally from the inside walls of the pool, the perimeter bonding grid must be continued under the adjacent unpaved perimeter surface.

If walls or other physical barriers prevent the perimeter from extending 3 feet beyond the inside walls of the pool, the bonding grid is required only to extend under the available perimeter area.

The perimeter bonding grid can comprise structural reinforcing metal (rebar or welded wire mesh) that is conductive to the perimeter surface and installed in or under the perimeter surface.

Where structural reinforcing steel is not available, a single, bare, solid 8 AWG or larger copper conductor can be installed around the pool’s perimeter in an area measuring between 18 inches and 24 inches from the inside pool walls.

The 8 AWG bonding conductor can be installed in the paving material (i.e., in the concrete), or it can be buried in the
material (subgrade) below the paving material.

Where buried, the bonding conductor must not be less than 4 inches and not more than 6 inches below the surface level of the subgrade material.

If structural reinforcing steel is not available, another choice for bonding the perimeter surfaces is through the use of a grid comprising bare 8 AWG solid copper conductors installed to follow the contour of the perimeter surface.

The copper conductor grid pattern is arranged using the same space and tolerances as required for bonding grids installed for conductive pool shells in accordance with 680.26(B)(1)(b).

This requirement does not apply to decks constructed of non-conductive materials such as wood, plastic, or
fiberglass.

However, the perimeter surface under an elevated deck around a pool installed on or partially in the ground requires
bonding.

The required perimeter surface bond must be connected at four evenly spaced points around the pool perimeter to the conductive pool shell.

Connection between the perimeter surface bond and nonconductive pool shells is not required.

 

[nuttyp]

Thanks very much folks for all the replies and detail. So the first thing I now realize is that a bonding grid of some type is indeed required, whether or not poured concrete is below the pavers.

How do you know that there is no bonding?

Well I actually don't really know that - I just assumed that no grid is present because I dug this 12"x12" cube (pictured, for a new rail) ) and only found the one #8 stub protruding from the poured wall of the pool. Might be a bad assumption on my part, as it's possible there is more of a grid, or more wires, extending around the rest of the pool.

One of the photos in the post by @anthony21078 thread here: Ladder anchors don't have drainage shows a similar arrangement with no noticeable grid, and this alerted me to ask about my situation. It's possible his grid was installed after the picture was taken.

Now that I opened up this can-o-worms for myself, the build of my pool was ten years ago by the former owner, but I should be able to find the plans with the county. Not that plans=proof.

Thanks again! -- Joe

 

[PoolGate]

I believe there is an electrical way to test for a bonding wire.

 

[JamesW]

I should be able to find the plans with the county.

Ask for copies of the Permits and Inspections.

 

[anthony21078]

The pool in the first post is mine. When we pulled the old red bricks to put pavers and changed the coping, I re-installed the bonding wire in the same fashion it was previously installed. My pool was likely built in the late 80s and Im sure the NEC was different then. This pool did not have a grid. The old C coping had the bond wire attached to each piece of coping, ladder anchors, rails, light conduit and rebar at the 4 corners.